Effect of hyaluronidase and PEG chain conjugation on the biologic and antitumor activity of RNase A.

Subcutaneous application of bovine RNase A conjugated to HYase (bovine hyaluronidase), polyethylene glycol (PEG) and HYase+PEG resulted in a marked reduction of the width of the spermatogenic layers of the mouse testes. The number of sperms in caput epididymidis was significantly decreased in mice injected with conjugated RNase A. There was not any significant embryotoxic effect of free RNase A even conjugated with HYse, PEG and HYse+PEG.